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<head><meta charset="utf-8"><title>video stuttering · t-compiler/help · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/index.html">t-compiler/help</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html">video stuttering</a></h3>

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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214292217" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> lcnr <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214292217">(Oct 23 2020 at 09:41)</a>:</h4>
<p>Compiling <code>rustc</code> causes videos to stutter even with <code>low-priority = true</code> in <code>config.toml</code>.  Is there a way to decrease the priority even further or is it easier to just limit <code>x.py</code> to at most use all but a few threads?</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214292701" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214292701">(Oct 23 2020 at 09:46)</a>:</h4>
<p>I had that when I was using the BFS scheduler on Linux. Switching back to CFS fixed it for me. Which is the opposite of what's supposed to happen, but alas, computers.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313108" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Joshua Nelson <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313108">(Oct 23 2020 at 13:29)</a>:</h4>
<p>You could try -j2 maybe. I don't compile rustc on my main computer so I'm not sure.</p>



<a name="214313211"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313211" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313211">(Oct 23 2020 at 13:30)</a>:</h4>
<p>That would be very slow, I think <span class="user-mention" data-user-id="216206">@lcnr</span> has 24 hardware threads</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313241" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313241">(Oct 23 2020 at 13:30)</a>:</h4>
<p>I did try with -j20 back then and it didn't improve much</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313292" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313292">(Oct 23 2020 at 13:31)</a>:</h4>
<p>Linux scheduler is very weird, it never seems to work as well as I expect</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313296" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> lcnr <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313296">(Oct 23 2020 at 13:31)</a>:</h4>
<p>16 hardware threads <span aria-label="heart" class="emoji emoji-2764" role="img" title="heart">:heart:</span> currently using <code>-j 30</code> which seems to solve my issue</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313325" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313325">(Oct 23 2020 at 13:31)</a>:</h4>
<p>Oh, nice</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313356" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> lcnr <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313356">(Oct 23 2020 at 13:31)</a>:</h4>
<p>still want to look into changing my scheduler, but that's something I currently know nothing about so I am going to take my time there <span aria-label="sweat smile" class="emoji emoji-1f605" role="img" title="sweat smile">:sweat_smile:</span></p>



<a name="214313485"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313485" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Joshua Nelson <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313485">(Oct 23 2020 at 13:32)</a>:</h4>
<p>You can set the number of threads in config.toml so you don't need to pass it every time</p>



<a name="214313506"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313506" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Joshua Nelson <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313506">(Oct 23 2020 at 13:33)</a>:</h4>
<p>I think it's 'codegen units'</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313643" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313643">(Oct 23 2020 at 13:34)</a>:</h4>
<p>That is not the number of threads. You probably don't want to touch that; it won't help in the parallel bits.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/video%20stuttering/near/214313709" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/video.20stuttering.html#214313709">(Oct 23 2020 at 13:35)</a>:</h4>
<p>It's sort of an approximation of "per-rustc parallelism" but since you can have multiple rustcs running at once it's not really the right thing.</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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